You are not logged in. To discriminate your posts from the rest, you need to pick a nickname. (The uniqueness of nickname is not reserved. It is possible that someone else could use the exactly same nickname. If you want assurance of your identity, you are recommended to login before posting.) Login

You are not logged in. To discriminate your posts from the rest, you need to pick a nickname. (The uniqueness of nickname is not reserved. It is possible that someone else could use the exactly same nickname. If you want assurance of your identity, you are recommended to login before posting.) Login

I also have the same problem, also Eclipse 3.1M5, GEF 3.1, JDK 1.4.2, (WTP 1.0M3)
on Windows platform.

Here the stacktrace from the logfile:

java.lang.LinkageError: Class org/w3c/dom/Document violates loader constraints
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:537)
at org.eclipse.osgi.framework.internal.defaultadaptor.DefaultClassLoader.defineClass(DefaultClassLoader.java:312)
at org.eclipse.core.runtime.adaptor.EclipseClassLoader.defineClass(EclipseClassLoader.java:223)
at org.eclipse.osgi.framework.internal.defaultadaptor.DefaultClassLoader.findClassImpl(DefaultClassLoader.java:295)
at org.eclipse.osgi.framework.internal.defaultadaptor.DefaultClassLoader.findClass(DefaultClassLoader.java:176)
at org.eclipse.osgi.framework.adaptor.core.AbstractClassLoader.findLocalClass(AbstractClassLoader.java:221)
at org.eclipse.core.runtime.adaptor.EclipseClassLoader.basicFindLocalClass(EclipseClassLoader.java:135)
at org.eclipse.core.runtime.adaptor.EclipseClassLoader.findLocalClass(EclipseClassLoader.java:59)
at org.eclipse.osgi.framework.internal.core.BundleLoader.findLocalClass(BundleLoader.java:331)
at org.eclipse.osgi.framework.internal.core.BundleLoader.findClass(BundleLoader.java:357)
at org.eclipse.osgi.framework.adaptor.core.AbstractClassLoader.loadClass(AbstractClassLoader.java:94)
at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:302)
at tk.eclipse.plugin.jspeditor.editors.TLDLoader.getTLDFromWebXML(TLDLoader.java:78)
at tk.eclipse.plugin.jspeditor.editors.TLDLoader.get(TLDLoader.java:42)
at tk.eclipse.plugin.jspeditor.editors.TLDInfo.<init>(TLDInfo.java:75)
at tk.eclipse.plugin.jspeditor.editors.TLDInfo.getTLDInfo(TLDInfo.java:46)
at tk.eclipse.plugin.jspeditor.editors.JSPInfo.<init>(JSPInfo.java:54)
at tk.eclipse.plugin.jspeditor.editors.JSPAssistProcessor.update(JSPAssistProcessor.java:112)
at tk.eclipse.plugin.htmleditor.editors.HTMLSourceEditor.updateAssist(HTMLSourceEditor.java:221)
at tk.eclipse.plugin.htmleditor.editors.HTMLSourceEditor.update(HTMLSourceEditor.java:206)
at tk.eclipse.plugin.htmleditor.editors.HTMLSourceEditor.doSetInput(HTMLSourceEditor.java:285)
at org.eclipse.ui.texteditor.AbstractTextEditor$16.run(AbstractTextEditor.java:2284)
at org.eclipse.jface.operation.ModalContext.runInCurrentThread(ModalContext.java:344)
at org.eclipse.jface.operation.ModalContext.run(ModalContext.java:289)
at org.eclipse.jface.window.ApplicationWindow$1.run(ApplicationWindow.java:624)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:69)
at org.eclipse.jface.window.ApplicationWindow.run(ApplicationWindow.java:621)
at org.eclipse.ui.internal.WorkbenchWindow.run(WorkbenchWindow.java:2026)
at org.eclipse.ui.texteditor.AbstractTextEditor.internalInit(AbstractTextEditor.java:2302)
at org.eclipse.ui.texteditor.AbstractTextEditor.init(AbstractTextEditor.java:2329)
at tk.eclipse.plugin.htmleditor.editors.SplitPageHTMLEditor.createPartControl(SplitPageHTMLEditor.java:103)
at tk.eclipse.plugin.htmleditor.editors.HTMLEditor.createPartControl(HTMLEditor.java:93)
at org.eclipse.ui.internal.PartPane$2.run(PartPane.java:148)
at org.eclipse.core.internal.runtime.InternalPlatform.run(InternalPlatform.java:1015)
at org.eclipse.core.runtime.Platform.run(Platform.java:757)
at org.eclipse.ui.internal.PartPane.doCreateChildControl(PartPane.java:144)
....

And the stacktrace of the immediately following error:

java.lang.NullPointerException
at tk.eclipse.plugin.htmleditor.editors.HTMLSourceEditor.addTextListener(HTMLSourceEditor.java:107)
at tk.eclipse.plugin.htmleditor.editors.HTMLOutlinePage.createControl(HTMLOutlinePage.java:58)
at org.eclipse.ui.views.contentoutline.ContentOutline.doCreatePage(ContentOutline.java:134)
at org.eclipse.ui.part.PageBookView.createPage(PageBookView.java:315)
at org.eclipse.ui.part.PageBookView.partActivated(PageBookView.java:613)
at org.eclipse.ui.internal.PartListenerList$1.run(PartListenerList.java:52)
at org.eclipse.core.internal.runtime.InternalPlatform.run(InternalPlatform.java:1015)
at org.eclipse.core.runtime.Platform.run(Platform.java:757)
at org.eclipse.ui.internal.PartListenerList.firePartActivated(PartListenerList.java:50)
at org.eclipse.ui.internal.WorkbenchPage.firePartActivated(WorkbenchPage.java:1500)
at org.eclipse.ui.internal.WorkbenchPage.setActivePart(WorkbenchPage.java:2821)
....

You are not logged in. To discriminate your posts from the rest, you need to pick a nickname. (The uniqueness of nickname is not reserved. It is possible that someone else could use the exactly same nickname. If you want assurance of your identity, you are recommended to login before posting.) Login

You are not logged in. To discriminate your posts from the rest, you need to pick a nickname. (The uniqueness of nickname is not reserved. It is possible that someone else could use the exactly same nickname. If you want assurance of your identity, you are recommended to login before posting.) Login

You are not logged in. To discriminate your posts from the rest, you need to pick a nickname. (The uniqueness of nickname is not reserved. It is possible that someone else could use the exactly same nickname. If you want assurance of your identity, you are recommended to login before posting.) Login